Hypertensive disorders in pregnancy are divided into the following five categories: 1. hypertension in pregnancy: the first elevation of blood pressure during pregnancy, systolic blood pressure ≥ 140 mmHg or diastolic blood pressure ≥ 90 mmHg, and negative proteinuria is diagnosed when blood pressure returns to normal within 12 weeks after delivery; 2. preeclampsia: after 20 weeks of pregnancy, systolic blood pressure ≥ 140 mmHg and/or diastolic blood pressure ≥ 90 mmHg, 24 hours urine protein amount ≥ 0.3g or random urine protein qualitative (+), which may be accompanied by epigastric discomfort or thrombocytopenia; 3, eclampsia: patients with preeclampsia present with prenatal or postnatal convulsions that cannot be explained by other causes; 4, chronic hypertension complicated by preeclampsia: pregnant women with hypertension are negative for proteinuria before 20 weeks of gestation, but develop urine protein after 20 weeks of gestation. Or proteinuria before 20 weeks of gestation and a sudden increase in urinary protein after 20 weeks of gestation. Or thrombocytopenia and further increase in blood pressure. Or other serious manifestations such as liver and kidney function impairment, pulmonary edema, neurological abnormalities, visual impairment, etc.; 5. Combined chronic hypertension in pregnancy: systolic blood pressure ≥ 140 mmHg and/or diastolic blood pressure ≥ 90 mmHg before 20 weeks of gestation, and hypertension was still diagnosed after 20 weeks of gestation and persisted until 12 weeks postpartum.